Add json::from_json().

src/json.cpp

@@ -18,6 +18,7 @@
 #include "fs-compat.hpp"
 #include "types.hpp"
 
+#include <nlohmann/detail/exceptions.hpp>
 #include <nlohmann/json.hpp>
 
 namespace FediBlock::json
@@ -43,4 +44,22 @@ string pull_request_body(string_view branch, const entry_type &entry)
     return json.dump();
 }
 
+entry_type from_json(const string_view json_string)
+{
+    const auto json{nlohmann::json::parse(json_string.data())};
+    entry_type entry;
+    entry.description = json[0].at("description").get<string>();
+    entry.instance = json[0].at("instance").get<string>();
+    entry.receipts = json[0].at("receipts").get<vector<string>>();
+    try
+    {
+        entry.screenshot_filepath = json[0].at("screenshot").get<string>();
+    }
+    catch (const nlohmann::detail::out_of_range &) // Ignore missing screenshot.
+    {}
+    entry.tags = json[0].at("tags").get<vector<string>>();
+
+    return entry;
+}
+
 } // namespace FediBlock::json

src/json.hpp

@@ -35,6 +35,9 @@ using std::string_view;
 [[nodiscard]] string pull_request_body(string_view branch,
                                        const entry_type &entry);
 
+// Convert a JSON string into an entry_type.
+[[nodiscard]] entry_type from_json(string_view json_string);
+
 } // namespace FediBlock::json
 
 #endif // FEDIBLOCK_BACKEND_JSON_HPP